Thank You for the detailed posts Sir.Hari Nair wrote:The LCH is designed to meet a specific percentile of crashworthiness, as defined in Mil Standard .
Towards this:
- The landing gear oleos have a two-stage design. The first stage caters for normal operations. The second stage compression caters for the crash loads.
- The lower portion of the fuselage has a section that is designed to crush, to attenuate the crash loads, after the oleos have absorbed the initial impact and the fuselage contacts the surface.
- The seats for the Pilot and Weapon Systems Operator are crash-worthy. These seats are mounted on rails and stroke downwards to further reduce the acceleration. The seat loads are absorbed by its Variable Load Energy Absorbers. The idea being to finally reduce the 'g' load on the spine to below 14.
So, its essentially a three-stage approach - using the oleos, the crush portions and the seat for energy attenuation in the event of a crash with vertical velocities more than 2000 feet per minute.
- When up close, its very evident that the oleos and attachment points are beefy - they remind me in size, of those on the Mi-17: which is a 13 tonne helicopter!
- The testing of the LCH landing gear was done on a rig that was used to check out the Navy LCA's landing gear. However the rig had to be modified, since the LCH landing gear had to be dropped from a even higher height. The landing gear, with ballast representing the helicopter weight came down with a mighty crashing sound in the rig - it passed the test in a single go. My instinct tells me that its capable of taking more punishment and has a generous amount of over-design. Which is a good thing for an attack helicopter
Those landing gears indeed standout, One side-on look and they stand out. I often wondered why and now I get it. Also great to hear about the ACs. From a crew perspective this is a great thing.
Elsewhere at another discussion group we had some back and forth on the selection of rigid rotors for the LCH over semi rigid and fully articulate toros. May I request you to kindly further explain the choice of rigid rotors.
Regards